1. Field of the Invention
The present invention relates to a liquid crystal display technology, more particularly, to a driver for an LED backlight and an LED backlight module and a liquid crystal display (LCD).
2. Description of the Related Art
With the progress of technology, the backlight technology for LCDs continues to develop. A backlight for a conventional LCD uses cold cathode fluorescent lamps (CCFLs). Since the CCFL backlight has the disadvantages of poor color restoration ability, low luminous efficiency, high discharge voltage, unsatisfied discharge characteristics at low temperatures, long heating time before the grey level being stabilized, a backlight using LEDs has already been developed.
However, in the prior art LED backlight driver, the driving signal output by the constant current driver has a fixed frequency. Its spectrum energy is thus concentrated at the harmonic frequencies of the fundamental wave. In electromagnetic interference (EMI) test, the peak value tends to be excessive which is not conductive to satisfied EMI test result.